
function isNull(e) {
    return e == undefined || e == "undefined" || e == null || e == ""
}


function getImageList(Num, Pre, Ext) {
  var list = [];
  var ext = Ext || '.jpg';
  var pre = Pre || '';
  for(var i=1;i<=Num;i++) {
    list.push(pre + i + ext);
  }
  return list;
}

module.exports = {
    isNull: isNull,
    getImageList: getImageList
};